1. Field of the Invention
The present invention relates to a multiple access control method for guaranteeing a QoS requirement. More particularly, the present invention relates to an improved multiple access control method for guaranteeing a QoS requirement, which is capable of effectively implementing a time division multiple access (TDMA)-based dynamic reservation method for a wireless asynchrnous transfer mode (ATM) in a medium access control protocol.
2. Description of the Prior Art
In the conventional random access method, the priority which is implemented based on a delay time request of a traffic characteristic of a mobile station is not considered. Even through the priority is considered, it is difficult to implement a method for guaranteeing a reserved request delay time based on the priority.
In the US Patent "Medium Access Control Protocol for Wireless Network (Application No.: PCT/US94/00996, patent Ser. No. 94-17606, Jan. 27, 1994)", one of nodes for implementing a communication between the nodes is designated as a hub station, and the remaining nodes are designated as a remote station, so that a radio channel is effectively utilized in accordance with the control of the sub station.
An outbound period (toward a remote station direction), an inbound period (toward a hub station direction), and an interval between the outbound period and the inbound period are determined in a communication period between the hub station and the remote station. Therefore, an electric power is supplied to the hub and remote stations during a corresponding transfer/receiving time for thereby decreasing the consumption of the electric power. In addition, the radio channel is effectively used by controlling the number of transfers and period by enabling a remote operation based on the control of the hub station. There is provided an algorithm determining the hub station between the base stations.
In the above-described U.S. patent, the remote cells which transmit the identical traffics are disclosed based on a multicell packed technique by controlling the number of transfers to the remote station and a transfer time. However, there are problems in that it is impossible to decrease a cell delay variation when supporting a real time traffic based on an ATM network, and an accurate slot allocation is not implemented.
Next, In the European Patent "An Adaptive medium access scheme for wireless LAN (Application No.: 94105695.2, patent Ser. No.: 0 621 708 A2, Oct. 26, 1994", a medium access control method by which a plurality of remote stations can share a radio channel under a wireless LAN environment is disclosed. However, the medium access control is implemented based on a central control method, and the medium access control protocol is implemented using a reservation method for a user data traffic, and the control and signal traffic is implemented based on a random access method.
One communication period is divided into three time bands A, B and C. The A time band is utilized for a downstream data (from a reference direction toward a remote base direction), the B time band is utilized for a upstream data (from a remote station direction to a reference direction, and the C time band is utilized for a control and signal information transfer. The data slot allocations of the A and B time are implemented in the base station and are determined by a slot request from the remote direction. It is possible to increase the efficiency of the channel by dynamically controlling the duration of the A, B, and C time.
However, in the traffic characteristic of the mobile station for the random access method, the priority based on the delay request time is not considered. Even though the priority is considered, a method which is capable of guaranteeing a reservation request delay time based on the priority is not disclosed.